Color blindness, or color vision defects, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Color blindness affects a significant percentage of the population. There is no actual blindness but there is a deficiency of color vision. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive color in light and transmit that information to the optic nerve. This type of color blindness is usually a sex-linked condition. The genes that produce photopigments are carried on the X chromosome; if some of these genes are missing or damaged, color blindness will be expressed in males with a higher probability than in females because males only have one X chromosome.

Main Symptoms of Color Vision Defects include:
1. Difficulty in identify between colors
2. Unable to see a few shades of color
3. Unable to distinguish shades of red and green
4. In rare cases people see only black, white and gray.